In certain automotive vehicle designs, it is desirable to support the muffler body directly from the undercarriage of the vehicle rather than supporting it indirectly by hangers on stub pipes at the ends of the muffler. It has been previously proposed to support a muffler body from the undercarriage by a band clamp around the muffler body. In this prior proposal, the hanger clamp assembly is prone to failure at two different critical regions in the band clamp. First, this prior art band clamp is tightened around the muffler body by a clamping bolt which extends between the free ends of the clamp sleeve, the free ends being turned outwardly to form opposed flanges. This arrangement results in unsupported bending moments at the juncture of the flange with the sleeve so that the tensile stresses and bending stresses in that region are very high compared with the tensile stresses achieved in the sleeve surrounding the muffler. A second area of high bending stresses occur in the sleeve portion of the prior art clamp, adjacent its engagement with the hanger bracket which is supported from the undercarriage of the vehicle.
Band clamps are already known in the prior art which utilize a sleeve portion adapted to conform to the body being clamped and a channel portion with first and second sidewalls which are extensions of the sleeve portion and extend in a direction perpendicular to the adjacent sleeve portion. A force applying means includes a spline between the sidewalls and a bar outside each sidewall with a bolt for drawing the sidewalls into engagement with the spline to tighten the sleeve portion around the body. A band clamp of this type is disclosed in the Cassel U.S. Pat. No. 4,312,526 granted Jan. 26, 1982 and also in Cassel et al U.S. Pat. No. 4,623,164 granted Nov. 18, 1986.